glycine-derived aldimino esters is described. The asymmetric tandem conjugate addition–elimination procedure is characterized by its exceptional mild reaction conditions and features with an exquisite enantioselectivity profile using commercially available silver/DTBM-SegPhos catalyst, allowing for the facile preparation of a variety of substituted and chiral glutamicacid derivatives (up to 99% ee) bearing Schiff
New Efficient Synthesis of 2-Thioxo-2,3-dihydropyrimidin-4(1H)-ones from Baylis–Hillman Adducts
作者:Ying Zhong、Zhigang Zhao、Xiuhua Chen、Gang Huang
DOI:10.1055/s-0036-1591310
日期:2017.12
3-dihydropyrimidin-4(1H)-ones in good yields. Azides obtained from Baylis–Hillmanadducts were treated with triphenylphosphine to give the corresponding iminophosphoranes, which reacted with carbon disulfide at 40 °C to produce isothiocyanates. The reaction of these isothiocyanates with primary amines provided thiourea intermediates, which in the presence of potassium carbonate or sodium methoxide were
A highly regio- and stereoselective Pd-catalyzed electrocarboxylation of Baylis-Hillman acetates: An interesting switchable regioselectivity based on electrode material
regio- and stereoselective palladium catalyzed electrocarboxylation of Baylis-Hillman acetates. We found an interesting unprecedented electrode material-controlled switchable regioselectivity. When Platinum was taken as cathode, benzylic carboxylation products were found to be the predominant regioisomers (condition A). Under similar reaction conditions when Nickel was taken as cathode, a complete reversal
我们开发了一种新型的区域选择性和立体选择性钯催化 Baylis-Hillman 醋酸盐的电羧化反应。我们发现了一种有趣的、前所未有的电极材料控制的可切换区域选择性。当铂作为阴极时,发现苄基羧化产物是主要的区域异构体(条件 A)。在以镍为阴极的类似反应条件下,观察到区域选择性完全逆转,提供肉桂基羧化产物作为主要的区域异构体,仅具有 (E)-立体化学(条件 B)。我们提出了合理的机制来解释区域选择性的转换,这得到了 TEMPO 实验的进一步支持。
Organophotoredox-Catalyzed Intermolecular Formal Grob Fragmentation of Cyclic Alcohols with Activated Allylic Acetates
We have developed an efficientmethod that employs organophotoredox-catalyzed relay Grob fragmentation to facilitate the smooth ring-opening allylation of cyclic alcohols in an environmentally friendly manner. This protocol directly incorporates a wide spectrum of cyclic alcohols and activated allylic acetates into the cross-coupling reaction, eliminating the need for metal catalysts. The process yields